Synthesis of n-substituted indole-3-carboxylic acid derivatives via Cu(I)-catalyzed intramolecular amination of aryl bromides

A variety of N-alkylated and N-arylated derivatives of methyl 1H-indole-3-carboxylate were synthesized efficiently via Ullmann-type intramolecular arylamination, using the CuI-K3PO4-DMF system. This catalytic amination procedure can be performed with good to high yields under mild conditions under an air atmosphere.